Cookie stamp



FIG. 1 is a perspective view of a cookie stamp showing my new design;

FIG. 2 is a front view thereof, the rear view being a mirror image thereof;

FIG. 3 is a left side view thereof, the right side view being a mirror image thereof; and,

FIG. 4 is a top view thereof.

The broken lines illustrate portions of the cookie stamp that form no part of the claimed design. 

CLAIM The ornamental design for a cookie stamp, as shown and described. 